Lawford wasn’t in this movie, and there’s a little more to that story than Christmas cheer. Per Wikipedia:

Peter Lawford was originally cast as Alan A. Dale, but when Lawford’s brothers-in-law, John F. Kennedy and Robert Kennedy, opted to stay at Lawford’s house during a West Coast trip instead of at Sinatra’s as originally planned — Sinatra had built a helipad and made countless other arrangements for the eagerly awaited presidential visit — a furious Sinatra ostracized Lawford from the Rat Pack. Bing Crosby ended up cast in Lawford’s role.

This is one of those not-quite-right Wikipedia moments: JFK stayed at Bing Crosby’s house, not Lawford’s. But Lawford was the one who delivered the bad news to Sinatra, and Sinatra killed the messenger.

Sinatra was close with certain mobsters, including the notorious Sam Giancana, and the Kennedy administration was fighting organized crime at the time. Bobby Kennedy, as Attorney General, put the kibosh on JFK staying with Sinatra — saying the president “couldn’t stay at Frank’s and sleep in the same bed that [Sam] Giancana or any other hood had slept in,” as Lawford later put it to Kitty Kelley.

None of this explains why Bing Crosby got Lawford’s role in the movie, since Crosby was the guy that Kennedy stayed with. Perhaps it was tit-for-tat on Sinatra’s part: “JFK stayed with Crosby instead of me, so I’m casting Crosby instead of you.” Whatever. By the time the movie came out, JFK had been killed and Sinatra had switched to the Republican party.

Maybe it’s not such a cheery story after all. Happy holidays, everyone!